CoreLogic Report Highlights Storm Surge Risk

CoreLogic Report Highlights Storm Surge Risk

Insurance industry research firm CoreLogic has released a
second annual study of the storm surge flooding risk to highly
populated coastal areas. Like last year’s study, this
year’s edition,
“
2011 CoreLogic&reg; Storm Surge Report
: Residential
Storm-Surge Exposure Estimates for 10 U.S. Cities,”
zeroes in on heavily built-up population centers —
coastal cities where the potential dollar value of losses that
could occur in a worst-case hurricane landfall scenario are
huge.
But this year’s report also goes a step farther
than last year’s, comparing the footprint of
properties vulnerable to a possible flood against the flood
zone database maintained by the Federal Emergency Management
Agency (FEMA). The study’s conclusion will come as no
surprise to anyone who has taken a close look at
FEMA’s flood zones: many, if not most, of the coastal
properties that could be damaged or destroyed by storm surge
flooding in a major hurricane lie outside of FEMA’s
official flood zone, and are likely to be uninsured.
Above, CoreLogic’s graphical representation of the
storm surge risk to the Charleston, S.C., area. Red zones are
most likely to be hit by a storm surge flood; higher elevations
represent a greater property dollar value.
Interestingly, the greatest potential economic loss from a
really bad hurricane isn’t found in Florida or on the
shores of the Gulf of Mexico, but in the high-value, heavily
built-up shoreline of Long Island, N.Y. (which includes
Brooklyn). CoreLogic reports, “The findings show that
of the ten metro areas studied, Long Island has the most
residential property at risk with $99 billion of exposure,
followed by the Miami-Palm Beach region with $44.9 billion of
exposure and Virginia Beach with $44.6 billion of exposure. The
metro areas identified as having the lowest economic risk are
Mobile, Ala. with $3 billion of exposure and Corpus Christi,
Tex. with $4.7 billion. Among the densely populated coastal
regions with the highest number of individual properties at
risk are Virginia Beach, with nearly 289,000 properties, New
Orleans, with more than 278,000 properties and Tampa, with more
than 277,000 properties at risk.”
These are worst case numbers, of course, and the odds are
strongly against the worst case occurring in even one location,
much less in all ten cities in a single year. But that all
depends on the weather. Hurricane forecasters have already
begun to predict the intensity of the 2011 season, and this
year, they say, is shaping up to be a bad one. Colorado State
University researchers say conditions favor the formation of
nine hurricanes this year in the Atlantic basin, including five
major hurricanes
(“
Colorado State University Forecasters Predict AboveAverage 2011
Atlantic Hurricane Season
”).
Last year’s hurricane season fizzled — at
least if we’re talking about hurricanes that strike
land. Despite predictions of a heavy season, 2010 was the fifth
year in a row that no major hurricane made landfall in the U.S.
(“
Hurricane Season Slides By And the U S Dodges the Bullet
).
That good luck was brought about by what researcher Jeff
Masters called “friendly steering currents”
— an established jet stream pattern in 2010 that
tended to curve storms into the north Atlantic, rather than
permit them to push on towards the U.S. mainland.
But 2010 also saw the unusual occurrence of a Category 1
hurricane striking the province of Newfoundland, Canada. So
while the steering currents did push almost every storm out to
sea, they pushed that one storm into land on a far more
northerly track than is typical. So if the steering currents
Masters described happen to be in force in 2011 — but
not quite as strongly — this year’s
hurricanes could very well curve north just far enough to hit
some of the high-value targets mentioned in the CoreLogic
report: New York’s Long Island suburbs, Tidewater
Virginia, or Charleston.
There’s no way to predict that, of course. Under
the circumstances, it’s probably wisest to heed the
advice of Colorado State’s Phil Klotzbach:
“It is recommended that all vulnerable coastal
residents make the same hurricane preparations every year,
regardless of how active or inactive the seasonal forecast is.
It takes only one landfall event near you to make this an
active season.”